Shopping for a laptop

I'm looking for a good laptop that can be used for music production. I want to run plugins like Amplitube 5, Kontakt 8, Reaktor 6, Serum 2, Omnisphere 3 and the Artuira V Collection. I'm okay with freezing and rendering those plugins but I want to be able to run them through a lot of effects such as Ozone 11, Fabfilter, Soundtoys Collection, and various other multi effect plugins. What are the specs I should be looking for?